Manufacturing method of electro-optical apparatus substrate, manufacturing method of electro-optical apparatus, electro-optical apparatus substrate, electro-optical apparatus, and electronic instrument
A manufacturing process of an electro-optical apparatus substrate is provided wherein a substrate is coated with a photosensitive resin. A first exposure process is executed with a first reticle to form an uneven portion on the substrate. Subsequently, a second exposure process is executed with a second reticle to remove all the photosensitive resin on portions other than the uneven portion. After the second exposure process, the substrate is developed so as to form an underlying film having an uneven portion.
This application claims priority to Japanese Patent Application Nos. 2003-374280 filed Nov. 4, 2003, and 2004-184090 filed Jun. 22, 2004 which are hereby expressly incorporated by reference herein in their entirety.
BACKGROUND1. Technical Field
The present invention relates to electro-optical apparatuses, and in particular relates to a transflective electro-optical apparatus capable of reflective display by reflecting incident light from an observing side as well as capable of transmissive display by transmitting incident light from a back face.
2. Related Art
A transflective liquid crystal device, which is a kind of electro-optical apparatus, includes a transflective layer that transmits light from a backlight located between a liquid crystal layer and a backlight unit, and also reflects external light. This transflective layer includes at least one opening for transmitting light from the backlight. The transflective layer also includes an uneven reflection surface for diffusing external light so as to prevent an observer from being mirrored on the screen.
A method for making the uneven reflection surface is described in Japanese Unexamined Patent Application Publication No. 2003-75987, for example. In this method, as shown in
In the method disclosed in Publication No. 2003-75987, a series of processes (“application of a photosensitive resin, exposure to light, development, and post-baking”) are performed twice to make the reflection layer 560. When the number of the processes is large like this, manufacturing takes a long time which increases manufacturing cost. In order to reduce the manufacturing period and cost, a method may be applied to eliminate the secondary series. In this case, the reflection layer 560 is formed on the substrate 500 and an underlying film 540a made in the first series. However, with only the first series, as shown in
The present invention has been made with such problems as a background, and it is an object of the invention to provide a manufacturing method of an electro-optical apparatus substrate, a manufacturing method of an electro-optical apparatus including the manufacturing method of the electro-optical apparatus substrate, the electro-optical apparatus substrate, the electro-optical apparatus using the electro-optical apparatus substrate, and an electronic instrument, which are capable of removing a photosensitive resin formed on an uneven portion to a depth smaller than the film thickness of the photosensitive resin while not leaving the photosensitive resin on portions other than the uneven portion.
SUMMARYTo solve the problems mentioned above, in a manufacturing method of an electro-optical apparatus substrate having an uneven light-reflection part according to the present invention, the method includes the steps of applying a positive photosensitive material on a substrate; exposing the photosensitive material with light for making unevenness so as to form a region corresponding to a convex portion of the light-reflection part so that the light acts until a depth smaller than that of a film thickness of the photosensitive material; exposing the outside of a region to be the electro-optical apparatus substrate with light for making the substrate so that the light acts until a depth larger than that of the film thickness of the photosensitive material applied in the applying process; developing the photosensitive material exposed to light so as to remove the region exposed during exposure; and forming a reflection layer with light reflectivity on an uneven surface formed on the photosensitive material in the developing process.
According to the manufacturing method of an electro-optical apparatus substrate, the depth of a concave portion of the uneven surface formed on the photosensitive material is smaller than the film thickness of the photosensitive material, and the photosensitive material in an area outside the region to be the electro-optical apparatus substrate is removed, so that side faces of the electro-optical apparatus substrate become flat. Since the depth of the concave portion of the uneven surface is less than the film thickness of the photosensitive material, the reflection layer formed on the bottom of the concave portion does not become flat, thereby achieving excellent scattering characteristics. Also, since the side faces of the electro-optical apparatus substrate become flat, a problem is solved in that an electrode arranged so as to overpass the side faces is not broken off.
According to the manufacturing method, in the exposing process for the substrate, in order to produce an opening for transmitting light within the region to be the electro-optical apparatus substrate, an area in the region to be the electro-optical apparatus substrate corresponding to the opening may also be exposed with light in addition to the outside of the region to be the electro-optical apparatus substrate.
In order to solve the problems mentioned above, in a manufacturing method of an electro-optical apparatus substrate having an uneven light-reflection part according to the present invention, the method includes the steps of applying a negative photosensitive material on a substrate; exposing the photosensitive material applied in the applying process with light for making unevenness so as to form a region corresponding to a convex portion of the light-reflection part so that the light acts until a depth smaller than that of a film thickness of the photosensitive material; exposing the substrate with light for forming a region to be the electro-optical apparatus substrate so that the light acts until a depth larger than that of the film thickness of the photosensitive material by excluding the light from the outside of the region to be the electro-optical apparatus substrate; developing the photosensitive material exposed to light and removing the region shielded during exposure; and forming a reflection layer with light reflectivity on an uneven surface formed on the photosensitive material in the developing process.
According to the manufacturing method of an electro-optical apparatus substrate, the depth of a concave portion of the uneven surface formed on the photosensitive material is smaller than the film thickness of the photosensitive material, and the photosensitive material in an area outside the region to be the electro-optical apparatus substrate is removed, so that side faces of the electro-optical apparatus substrate become flat. Since the depth of the concave portion of the uneven surface is less than the film thickness of the photosensitive material, the reflection layer formed on the bottom of the concave portion does not become flat, thereby achieving excellent scattering characteristics. Also, since the side faces of the electro-optical apparatus substrate become flat, a problem is solved in that an electrode arranged so as to overpass the side faces is not broken off.
According to the manufacturing method, in the exposing process for the substrate, in order to produce an opening for transmitting light within the region to be the electro-optical apparatus substrate, an area in the region to be the electro-optical apparatus substrate corresponding to the opening may also be excluded from light in addition to the outside of the region to be the electro-optical apparatus substrate.
Also, according to the manufacturing method, the exposing process for making the unevenness may be carried out with a stepper while the exposing process for the substrate may also be performed with the stepper or with a full plate exposure.
Also, the present invention provides a manufacturing method of an electro-optical apparatus including the manufacturing method of the electro-optical apparatus substrate. According to the manufacturing method of the electro-optical apparatus, since the depth of the concave portion of the uneven surface is less than the film thickness of the photosensitive material in the manufacturing process, the reflection layer formed on the bottom of the concave portion does not become flat, achieving excellent scattering characteristics. Also, since the side faces of the electro-optical apparatus substrate become flat, a problem is solved in that an electrode arranged so as to overpass the side faces is not broken off.
The present invention provides an electro-optical apparatus substrate including an underlying film having an uneven surface; and a light-reflection layer with light reflectivity, wherein the light-reflection layer is arranged on the uneven surface of the underlying film, side faces of the underlying film are flat, and the depth of a concave portion in the uneven surface of the underlying film is smaller than the film thickness of the underlying film. In such an electro-optical apparatus substrate, since the depth of the concave portion of the uneven surface is smaller than the film thickness of a photosensitive material, a reflection layer formed on the bottom of the concave portion does not become flat, so that excellent scattering characteristics can be achieved. Also, since side faces of the electro-optical apparatus substrate become flat, a problem is solved in that an electrode arranged so as to overpass the side faces is not broken off.
Preferably, the electro-optical apparatus substrate may include a light-exclusion layer made of a black resin material for shielding light, and the light-exclusion layer may be arranged on a predetermined region of the uneven surface of the underlying film.
Preferably, the electro-optical apparatus substrate may include a light-exclusion layer made of a metallic material for shielding light, and the light-exclusion layer may be arranged on a predetermined region of the uneven surface of the underlying film.
Also, preferably, the electro-optical apparatus substrate may include a light-exclusion layer formed by depositing a colored resin for shielding light, and the light-exclusion layer may be arranged on a predetermined region of the uneven surface of the underlying film.
Also, preferably, the electro-optical apparatus substrate may include the underlying film made of a positive photosensitive material.
Also, preferably, the electro-optical apparatus substrate may include the underlying film made of a negative photosensitive material.
Furthermore, the present invention provides an electro-optical apparatus including an electro-optical apparatus substrate and an electronic instrument including the electro-optical apparatus as a display. The side faces of the above-mentioned electro-optical apparatus substrate become flat in the manufacturing process, so that a problem is solved in that an electrode arranged so as to overpass the side faces is not broken off. Hence, yield is excellent and manufacturing cost is reduced, thereby reducing the manufacturing cost of the electro-optical apparatus including an electro-optical apparatus substrate and the electronic instrument including the electro-optical apparatus as a display.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 5(a)-(d) include drawings showing states of each process in the manufacturing method.
FIGS. 6(a)-(c) include drawings showing states of each process in the manufacturing method.
FIGS. 9(a)-(d) include drawings showing states of each process in a manufacturing method according to a modified embodiment.
FIGS. 14(a)-(e) include drawings showing states of each process in a conventional manufacturing process of the electro-optical apparatus substrate.
DETAILED DESCRIPTIONEmbodiments according to the present invention will be described below with reference to the drawings. In the drawings below, the component elements, sizes and proportions are changed from the actual structure to easy viewing.
Structure of Liquid Crystal Device
First, a liquid crystal device 100 according to an embodiment of the present invention will be described.
The backlight unit 104 includes a light guide plate 106 and a light source 105 such as a cold-cathode ray tube. The light source 105 irradiates a side face of the light guide plate 106 which is a plate member with light. On a surface of the light guide plate 106 facing the liquid crystal panel 102, a diffusing plate (not shown) is bonded for uniformly diffusing light from the light guide plate 106 on the liquid crystal panel 102. On the opposite surface, a reflection plate (not shown) is bonded for reflecting light to be emitted toward the back face to the liquid crystal panel 102, so that incident light from the side face is uniformly led to the second substrate 120 of the liquid crystal panel 102.
The first substrate 110 of the liquid crystal panel 102 is an optically transparent plate member such as glass. On the observing-side surface of the first substrate 110, a retardation film 111 (not shown in
The second substrate 120 is an optically transparent plate member such as glass. On the back face-side surface of the second substrate 120, a retardation film 121 (not shown in
The underlying film 130 is shaped by exposing and developing a photosensitive material, and its side faces 130a are flat. The underlying film 130 is provided with light-transmission openings 125, each being located around the center of each dot 160, and a smooth uneven surface 130b (referred to as the uneven surface below) formed in the observing side.
The transflector 140 is made by depositing a light-reflection material, such as aluminum or silver, on the observing-side surface of the underlying film 130 so as to have a thin film with a substantially predetermined thickness as shown in the plan view and the sectional view in
The color filters 150R, 150G, and 150B are resin layers provided corresponding to each of the dots 160. Each color filter is colored with pigment or the like with any color of red (R), green (G), and blue (B) so as to selectively transmit light with a wavelength corresponding to its color. Symbols (R), (G), and (B) in
Light-exclusion layers 151 made of a black resin material having carbon black dispersed therein or a metallic material, such as chrome (Cr), are arrayed in a lattice so as to bridge the clearances between the color filters 150R, 150G, and 150B so that the layers 151 shield side faces adjacent thereto of the color filters 150R, 150G, and 150B. The light-exclusion layer 151 is not limited to a specific material, and it can also be formed by overlapping two or three coloring layers of the color filters 150R, 150G, and 150B constituting the color layer, that is, by depositing these layers.
Each of a plurality of the data lines 152 is a band-shaped electrode made of a light-transmission conductive material, such as ITO. As shown in
The first substrate 110 and the second substrate 120 structured as described above, as shown in
Manufacturing Method
Next, a manufacturing method of the electro-optical apparatus substrate 124 according to the embodiment of the present invention will be described.
In this manufacturing process, first, the second substrate 120 is cleaned, and then dried (Process P1 in
Then, the pre-baked positive photosensitive resin 132 is exposed using a reticle 145 patterned as shown in
Using such a reticle 145, if the photosensitive resin 132 is exposed for 1,600 ms, for example, light transmitted through the reticle 145, as shown in
After exposing the entire second substrate 120 by successively displacing the reticle 145 with the stepper so as to repeat the exposure, exposure is made using a reticle 148 (Process P6 in
In the reticle 148, a portion corresponding to the panel display area is shielded, and the reticles 148 are arranged in the same matrix pattern corresponding to each dot 160 in the liquid crystal panel 102. As shown in the enlarged view of
After finishing the developing process of the photosensitive resin 132, the photosensitive resin 132 is successively irradiated with ultraviolet rays (referred to as UV below), such as i rays. The photosensitive resin 132 (PC 405G) used in the embodiment has a tinge of yellow, and by the UV irradiation, the tinge of yellow is eliminated so as to improve the optical transparency. The purpose is for helping to solve the problem in that if the underlying film 130 is assumed to have color, the reflection light should reflect the color when external light is reflected in the electro-optical apparatus substrate 124. In addition, this is a specific process for the photosensitive resin 132 used according to the embodiment, and is not indispensable to the manufacturing process of the electro-optical apparatus substrate 124. Then, the photosensitive resin 132 is baked at a temperature of 220° C. for 50 min, for example (Process P8 in
Then, as shown in
Subsequently, a method for building components on the second substrate 120 having the transflective layer 140 formed thereon will be described with reference back to
Each of the red, green and blue color filters 150R, 150G, and 150B is applied in a matrix pattern continuously on the transflective layer 140 of the second substrate 120. These color filters 150R, 150G, and 150B may be made of a photosensitive resin colored with pigments, for example. Then, a thin film made of ITO is produced so as to cover the color filters 150R, 150G, and 150B and the light-exclusion layer 151 for producing the data lines 152 by patterning the thin film. Since the side faces 130a in the electro-optical apparatus substrate 124, become flat by removing portions of the photosensitive resin corresponding to the out of the panel display area in the developing process, there is no problem with the breaking off of data lines arranged out of the panel display area so as to overpass the side faces 130a. Thus, the quality of the electro-optical apparatus substrate 124 is improved, resulting in a quality improvement of the liquid crystal device 100. Then, after the data lines are formed, the alignment layer 154 is produced so as to cover the data lines 152, and a rubbing treatment is applied on the surface of the alignment layer 154.
The manufacturing method of the components/produced on the second substrate 120 has been described. The second substrate 120 obtained with the manufacturing method and the first substrate 110 having the pixel electrodes 114, the scanning lines 116, the TFD elements 115, and the alignment layer 118 produced thereon are bonded together with the sealing compounds 170 therebetween in a state that the alignment layer 118 opposes the alignment layer 154. Then, the liquid crystal 180 is injected into a space surrounded by the substrate 110, the substrate 120, and the sealing compounds 170, and thereafter, the space containing the liquid crystal 180 injected therein is sealed with a sealant (not shown). Then, on the external surfaces of the first substrate 110 and the second substrate 120 integrated with each other, the retardation films 111 and 121 and the polarizers 112 and 122 are bonded so as to complete the liquid crystal panel.
As described above, according to the manufacturing method of the embodiment, since the concave portions of the uneven surface formed on the underlying film 130 do not reach the second substrate, the concave portions of the transflective layer 140 do not become flat. Hence, in the transflective layer 140, no mirror-reflective portion exists, so that excellent scattering characteristics can be achieved. Also, since the photosensitive resin in a portion out of the panel display area is removed so that the side faces 130a of the electro-optical apparatus substrate 124 become flat, the data lines 152 arranged so as to overpass the side faces 130a are not broken off.
Modifications
One embodiment of the present invention has been described. However, the present invention is not limited to the embodiment described above, and various modifications can be made. For example, the embodiment may be modified as follows.
According to the embodiment, the electro-optical apparatus substrate 124 is manufactured using a positive photosensitive material, which becomes soluble by exposure to light; alternatively, a negative photosensitive material may be used, which becomes insoluble by exposure to light.
Then, the secondary exposure is carried out using a reticle 148A.
According to the embodiment described above, the depth through which light acts on the photosensitive material is controlled with an exposure time. Alternatively, the depth may be controlled by changing light intensity.
Also, according to the embodiment described above, the photosensitive material is exposed to light with the stepper in that the reticle 145 and the reticle 148 are sequentially displaced for exposing. Alternatively, a full plate exposure may be used in that by preparing a mask for forming the uneven surface 130b by covering the entire second substrate 120 and a mask for forming the openings 125 and a portion out of the panel display area by covering the entire second substrate 120, the entire second substrate 120 is exposed to light in the first exposure process and in the secondary exposure process, respectively using one mask each. Also, in the first exposure process, the substrate may be exposed with the stepper like in the above embodiment while in the secondary exposure process, as shown in
In the manufacturing method described above, the first exposure may be performed with the reticle 148 for 4,000 msec while the secondary exposure may be performed with the reticle 145 for 1,600 msec. Also, in the manufacturing method described above, the reticle 148 is provided with the light-transmission sections 149a. However, the reticle 148 may not be provided with the light-transmission sections 149a. In the substrate manufactured in such a way, the film thickness of the reflection layer may be a thickness through which light from the backlight unit 104 transmits.
An electronic instrument having the liquid crystal device 100 described above mounted thereon will be described.
Claims
1. A manufacturing method of an electro-optical apparatus substrate having an uneven light-reflection part, comprising the steps of:
- applying a positive photosensitive material on a substrate;
- exposing the photosensitive material with light for making unevenness so as to form a region corresponding to convex portions of the light-reflection part, the exposing being controlled so that the light acts to a depth that is smaller than a film thickness of the photosensitive material;
- exposing an outside region of the electro-optical apparatus substrate with light, the exposing being controlled so that the light acts to a depth that is larger than the film thickness of the photosensitive material;
- developing the photosensitive material to remove exposed photosensitive material; and
- forming a reflection layer on an uneven surface of the photosensitive material formed in the developing process.
2. The method according to claim 1, wherein in the exposing process for the substrate, an area corresponding to an opening for transmitting light within the region to be the electro-optical apparatus substrate is exposed with light in addition to the outside region.
3. A manufacturing method of an electro-optical apparatus substrate having an uneven light-reflection part, comprising the steps of:
- applying a negative photosensitive material on a substrate;
- exposing the photosensitive material with light for making unevenness to form a region corresponding to convex portions of the light-reflection part, the exposing being controlled so that the light acts to a depth that is smaller than a film thickness of the photosensitive material;
- exposing the substrate with light for forming a region to be the electro-optical apparatus substrate, the exposing being controlled so that the light acts to a depth that is larger than the film thickness of the photosensitive material and shading the outside region of the substrate from the light;
- developing exposed photosensitive material and removing regions shielded during exposure; and
- forming a reflection layer on an uneven surface of the photosensitive material formed in the developing process.
4. The method according to claim 3, wherein in the exposing process for the substrate, an area in the region to be the electro-optical apparatus substrate corresponding to an opening for transmitting light is shaded from light in addition to the outside region of the substrate.
5. The method according to claim 1, wherein the exposing process for making the unevenness is carried out with a stepper while the exposing process for the substrate is performed with one of the stepper and a full plate exposure.
6. An electro-optical apparatus substrate, comprising:
- an underlying film having an uneven surface; and
- a light-reflection layer with light reflectivity,
- wherein the light-reflection layer is arranged on the uneven surface of the underlying film, side faces of the underlying film are flat, and a depth of concave portions in the uneven surface of the underlying film is smaller than a film thickness of the underlying film.
7. An electro-optical apparatus substrate, comprising:
- an underlying film with flat side faces and a region having an uneven surface;
- a light-reflection layer with light reflectivity; and
- a light-exclusion layer for shielding light,
- wherein the light-exclusion layer is arranged on a predetermined region of the uneven surface of the underlying film, the light-reflection layer is arranged on the uneven surface of the underlying film, and a depth of concave portions in the uneven surface of the underlying film is smaller than a film thickness of the underlying film.
8. The electro-optical apparatus substrate according to claim 7 wherein the light-exclusion layer further comprises a black resin material.
9. The electro-optical apparatus substrate according to claim 7 wherein the light-exclusion layer further comprises a metallic material.
10. The electro-optical apparatus substrate according to claim 7 wherein the light-exclusion layer further comprises a colored resin.
11. An electro-optical apparatus substrate, comprising:
- an underlying film made of a positive photosensitive material with flat side faces and having an uneven surface; and
- a light-reflection layer with light reflectivity,
- wherein the light-reflection layer is arranged on the uneven surface of the underlying film, and a depth of concave portions in the uneven surface of the underlying film is smaller than a film thickness of the underlying film.
12. An electro-optical apparatus substrate, comprising:
- an underlying film made of a negative photosensitive material with flat side faces and having an uneven surface; and
- a light-reflection layer with light reflectivity,
- wherein the light-reflection layer is arranged on the uneven surface of the underlying film, and a depth of concave portions in the uneven surface of the underlying film is smaller than a film thickness of the underlying film.
13. An electro-optical apparatus, comprising:
- a pair of substrates opposing each other so as to sandwich an electro-optical substance therebetween;
- an electro-optical apparatus substrate disposed on one substrate of the pair of substrates for reflecting incident light from the opposing substrates; and
- an electrode arranged so as to overpass side faces of the electro-optical apparatus substrate for applying a voltage to the electro-optical substance,
- wherein the electro-optical apparatus substrate is the electro-optical apparatus substrate according to claim 6.
14. An electronic instrument comprising the electro-optical apparatus according to claim 13 as a display.
15. A manufacturing method of an electro-optical apparatus, comprising the manufacturing method of an electro-optical apparatus substrate according to claim 1.
Type: Application
Filed: Nov 3, 2004
Publication Date: Jun 9, 2005
Patent Grant number: 7224505
Inventors: Toshihiro Otake (Okaya-shi), Tomohiko Kojima (Toyoshina-machi), Hideki Kaneko (Shiojiri-shi), Toshinori Uehara (Matsumoto-shi), Tomoyuki Nakano (Toyoshina-machi), Keiji Takizawa (Toyshina-machi)
Application Number: 10/980,750